Ch. 1-3 Water, Acids, Bases, Buffers Flashcards
Maximum number of hydrogen bonds of a water molecule
4
What type of molecule is water
Polar
What type of charge does oxygen have and hydrogen have in a water molecule
Oxygen has two partial negative
Hydrogen is partial positive
What are the properties of water
Liquid water is cohesive Water has a high specific heat Water has a high heat of vaporization Water expands when it freezes Water is a versatile solvent
Water molecules stick together due to hydrogen bonds
Cohesion
Why does water have a high specific heat
Must break hydrogen bonds so it takes a lot of energy to raise 1 gram of water 1 degree Celsius
Why does water have a high heat of vaporization
Must break hydrogen bonds
Takes a lot of energy to convert liquid water into vapor
Why does water expand when it freezes
Because in solid state water molecule is locked into maximum number of hydrogen bonds, so it takes up more space and is also less dense
What type of compounds will water dissolve
Polar covalent and ionic compounds
Importance of waters cohesive properties
Transport water against gravity in plants
Higher surface tension
What is the hydronium and hydroxide concentration of pure water at equilibrium at 25 degree Celsius
1.0 x 10^-7 M
pH of 7 or neutral
What happens if you add hydronium ion to pure water
Removes hydroxide ion
Equilibrium shifts to the water molecule side
Hydronium concentration is greater than hydroxide concentration
What happens if you add hydroxide to pure water
Removes hydronium
Equilibrium shifts to water molecule side
Hydroxide concentration is greater than hydronium concentration
What happens if you add an amino or NH3
Reduces hydronium concentration forming ammonium
Hydronium and hydroxide concentration always equals
pH and pOH
10^-14
Weak acids or bases that minimize changes in pH
Buffers
What is the importance if buffers
Controls chemical reactions and maintains homeostasis
What is the major buffer system in blood
Bicarbonate buffer system
What is the chemical formula of the bicarbonate buffer system
H2O + CO2 yields H2CO3 yields HCO3- + H+
What is HCO3- in the bicarbonate buffer system
Bicarbonate ( weak base)
What is H2CO3 in the bicarbonate buffer system
Carbonic acid (weak acid)
Blood pH should be around?
7.38 and 7.42
What happens if you increase H+
Through fat metabolism or overdose on drugs
Equilibrium will shift away from hydronium ion
Increasing CO2
Which means increasing rate and depth of respiration
What happens if you increase rate and depth of respiration through hyperventilating
Decrease in CO2
Equilibrium would shift towards CO2
Therefore increasing it
Why is water a polar molecule
Opposite ends of molecule have opposite charges
Electronegativity
The clinging of water molecules to other substances
Adhesion
Why is water cohesive
Constantly forming new bonds
Process in which water transports water and dissolved nutrients in plants
Transpiration
Biological importance of waters high specific heat
Keeps temps on land and water within limits that permit life
What is biological
Importance of waters relatively high heat of vaporization
Evaporative cooling moderates earths climate
Homogeneous mixture of two or more substances
Solution
Dissolving agent
Solvent
Material being dissolved
Solute
Solution where water is solvent
Aqueous solution
Water loving;
Hydrophilic
Water fearing
Hydrophobic
pH range for most biological fluids
Exception of this range
6-8
Digestive juices of human stomach
